Alzheimer's Disease Drug Research Articles

Glucose-modified BSA/procyanidin C1 NPs penetrate the blood-brain barrier and alleviate neuroinflammation in Alzheimer's disease models

Alzheimer's disease (AD) is a chronic neurodegenerative disease with high prevalence, long duration and poor prognosis. The blood-brain barrier (BBB) is a physiologic barrier in the central nervous system, which hinders the entry of most drugs into the brain from the blood, thus affecting the efficacy of drugs for AD. Natural products are recognized as one of the promising and unique therapeutic approaches to treat AD. To improve the efficiency and therapeutic effect of the drug across the BBB, a natural polyphenolic compound, procyanidin C-1 (C1) was encapsulated in glucose-functionalized bovine serum albumin (BSA) nanoparticles to construct Glu-BSA/C1 NPs in our study. Glu-BSA/C1 NPs exhibited good stability, slow release, biocompatibility and antioxidant properties. In addition, Glu-BSA/C1 NPs penetrated the BBB, accumulated in the brain by targeting Glut1, and maintained the BBB integrity both in vitro and in vivo. Moreover, Glu-BSA/C1 NPs alleviated memory impairment of 5 × FAD mice by reducing Aβ deposition and Tau phosphorylation and promoting neurogenesis. Mechanistically, Glu-BSA/C1 NPs significantly activated the PI3K/AKT pathway and inhibited the NLRP3/Caspase-1/IL-1β pathway thereby suppressing neuroinflammation. Taken together, Glu-BSA/C1 NPs could penetrate the BBB and mitigate neuroinflammation in AD, which provides a new therapeutic approach targeting AD.

Hybrid Membrane-Coated Nanoparticles for Precise Targeting and Synergistic Therapy in Alzheimer's Disease.

The blood brain barrier (BBB) limits the application of most therapeutic drugs for neurological diseases (NDs). Hybrid cell membrane-coated nanoparticles derived from different cell types can mimic the surface properties and functionalities of the source cells, further enhancing their targeting precision and therapeutic efficacy. Neuroinflammation has been increasingly recognized as a critical factor in the pathogenesis of various NDs, especially Alzheimer's disease (AD). In this study, a novel cell membrane coating is designed by hybridizing the membrane from platelets and chemokine (C-C motif) receptor 2 (CCR2) cells are overexpressed to cross the BBB and target neuroinflammatory lesions. Past unsuccessful endeavors in AD drug development underscore the challenge of achieving favorable outcomes when utilizing single-mechanism drugs.Two drugs with different mechanisms of actions into liposomes are successfully loaded to realize multitargeting treatment. In a transgenic mouse model for familial AD (5xFAD), the administration of these drug-loaded hybrid cell membrane liposomes results in a significant reduction in amyloid plaque deposition, neuroinflammation, and cognitive impairments. Collectively, the hybrid cell membrane-coated nanomaterials offer new opportunities for precise drug delivery and disease-specific targeting, which represent a versatile platform for targeted therapy in AD.

Evaluating the efficacy and safety of Alzheimer's disease drugs: A meta-analysis and systematic review.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Dementia severity was assessed mainly through cognitive function, psychobehavioral symptoms, and daily living ability. Currently, there are not many drugs that can be selected to treat mild to moderate AD, and the value of drugs remains controversial. The aim of this study is to quantitatively evaluate the efficacy and safety of cholinesterase inhibitors (ChEIs), memantine, and sodium oligomannate (GV-971) in the treatment of patients with AD. Additionally, molecular docking analysis will be used to investigate the binding affinities of donepezil, galantamine, rivastigmine, and memantine with key receptor proteins associated with AD, including beta-amyloid (Abeta), microtubule-associated protein (MAP), apolipoprotein E4 (APOE4), and Mitofusin-2 (MFN2), to further validate the results of the meta-analysis. We obtained clinical trials characterized by randomization, placebo control, and double-blinded methodologies concerning ChEIs, memantine, and GV-971. Statistical analysis was performed using Review Manager Version 5.4 software. Molecular docking was also conducted to evaluate the results. All drugs improved the cognitive function, with the effect value ranging from -1.23 (95% CI -2.17 to -0.30) for 20 mg memantine to -3.29 (95% CI -4.14 to -2.45) for 32 mg galantamine. Although 32 mg galanthamine and GV-971 did not improve the clinicians' Global Impression of Change scale, other drugs showed significant results compared with placebo. On NPI, only 10 mg of donepezil and 24 mg of galantamine had improvement effects. On ADCS/ADL, only 20 mg memantine and 900 mg GV-971 had no significant difference from the placebo. Donepezil 5 mg and GV-971 900 mg did not increase the drug withdrawal rates due to various reasons or adverse reactions when compared to the placebo. Donepezil demonstrated superior binding to the protein and exhibited greater efficacy compared to other drugs. ChEIs, memantine, and GV-971 all can slow the progression of AD but have different effects on respective assessments. Donepezil and GV-971 were relatively well tolerated.

Brain-Permeable Immunoproteasome-Targeting Macrocyclic Peptide Epoxyketones for Alzheimer's Disease.

Previously, we demonstrated that linear peptide epoxyketones targeting the immunoproteasome (iP) could ameliorate cognitive deficits in mouse models of Alzheimer's disease (AD) independently of amyloid deposition. We also reported the first iP-targeting macrocyclic peptide epoxyketones, which exhibit improved metabolic stability compared with their linear counterparts. Here, we prepared additional macrocyclic peptide epoxyketones and compared them with existing macrocyclic iP inhibitors by assessing Caco2 cell-based permeability and microsomal stability, providing the four best macrocyclic iP inhibitors. We then evaluated the four compounds using the Ames test and the potency assays in BV2 cells, selecting compound 5 as our AD drug lead. When 5 was administered intravenously (40 mg/kg) or orally (150 mg/kg) into healthy BALB/c mice, we observed considerable iP inhibition in the mouse brain, indicating good blood-brain barrier permeability and target engagement. Combined results suggest that 5 is a promising AD drug lead that may need further investigation.

The Alzheimer's Knowledge Base: A Knowledge Graph for Alzheimer Disease Research.

As global populations age and become susceptible to neurodegenerative illnesses, new therapies for Alzheimer disease (AD) are urgently needed. Existing data resources for drug discovery and repurposing fail to capture relationships central to the disease's etiology and response to drugs. We designed the Alzheimer's Knowledge Base (AlzKB) to alleviate this need by providing a comprehensive knowledge representation of AD etiology and candidate therapeutics. We designed the AlzKB as a large, heterogeneous graph knowledge base assembled using 22 diverse external data sources describing biological and pharmaceutical entities at different levels of organization (eg, chemicals, genes, anatomy, and diseases). AlzKB uses a Web Ontology Language 2 ontology to enforce semantic consistency and allow for ontological inference. We provide a public version of AlzKB and allow users to run and modify local versions of the knowledge base. AlzKB is freely available on the web and currently contains 118,902 entities with 1,309,527 relationships between those entities. To demonstrate its value, we used graph data science and machine learning to (1) propose new therapeutic targets based on similarities of AD to Parkinson disease and (2) repurpose existing drugs that may treat AD. For each use case, AlzKB recovers known therapeutic associations while proposing biologically plausible new ones. AlzKB is a new, publicly available knowledge resource that enables researchers to discover complex translational associations for AD drug discovery. Through 2 use cases, we show that it is a valuable tool for proposing novel therapeutic hypotheses based on public biomedical knowledge.

Combining Mini-Mental State Examination and Montreal Cognitive Assessment for assessing the clinical efficacy of cholinesterase inhibitors in mild Alzheimer’s disease: a pilot study

Current drugs for Alzheimer’s Disease (AD), such as cholinesterase inhibitors (ChEIs), exert only symptomatic activity. Different psychometric tools are needed to assess cognitive and non-cognitive dimensions during pharmacological treatment. In this pilot study, we monitored 33 mild-AD patients treated with ChEIs. Specifically, we evaluated the effects of 6 months (Group 1 = 17 patients) and 9 months (Group 2 = 16 patients) of ChEIs administration on cognition with the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), and the Frontal Assessment Battery (FAB), while depressive symptoms were measured with the Hamilton Depression Rating Scale (HDRS). After 6 months (Group 1), a significant decrease in MoCA performance was detected. After 9 months (Group 2), a significant decrease in MMSE, MoCA, and FAB performance was observed. ChEIs did not modify depressive symptoms. Overall, our data suggest MoCA is a potentially useful tool for evaluating the effectiveness of ChEIs.

Racial and ethnic differences in plasma biomarker eligibility for a preclinical Alzheimer's disease trial.

In trials of amyloid-lowering drugs for Alzheimer's disease (AD), differential eligibility may contribute to under-inclusion of racial and ethnic underrepresented groups. We examined plasma amyloid beta 42/40 and positron emission tomography (PET) amyloid eligibility for the ongoing AHEAD Study preclinical AD program (NCT04468659). Univariate logistic regression models were used to examine group differences in plasma and PET amyloid screening eligibility. Of 4905 participants screened at time of analysis, 1724 were plasma eligible to continue in screening: 13.3% Hispanic Black, 24.7% Hispanic White, 20.8% non-Hispanic (NH) Asian, 24.7% NH Black, and 38.9% NH White. Plasma eligibility differed across groups in models controlling for covariates (odds ratio from 1.9 to 4.0 compared to the NH White reference group, P<0.001). Among plasma eligible participants, PET eligibility did not differ by group. These results suggest that prevalence of brain amyloid pathology differed, but that eligibility based on plasma was equally effective across racial and ethnic group members. Plasma amyloid eligibility is lower in underrepresented racial and ethnic groups. In plasma eligible adults, positron emission tomography eligibility rates are similar across race and ethnicity. Plasma biomarker tests may be similarly effective across racial and ethnic groups.

Synthesis and investigation of the cholinesterase inhibitory and antioxidant capacities of some novel N'-(quinolin-4-ylmethylene)propanehydrazides against Alzheimer's disease.

One of the worst long-term health issues of the past few decades is Alzheimer's disease (AD). Unfortunately, there are currently insufficient choices for treating and caring for AD, which makes it a popular subject for drug development research. Studies on the development of drugs for AD have primarily concentrated on the use of multitarget directed ligands.Following this strategy, we designed new ChE inhibitors with additional antioxidant and metal chelator effects. In this research, eight novel N'-(quinolin-4-ylmethylene)propanehydrazide derivatives were synthesized and characterized. We then evaluated the inhibition potency of all the final compounds for cholinesterase enzymes. Among them, 4e (IC50 acetylcholinesterase[AChE] = 0.69 µM and butyrylcholinesterase[BChE]= 26.00 µM) and 4h (IC50's AChE= 7.04 µM and BChE= 16.06 µM) were found to be the most potent AChEand BChEinhibitors, respectively.

PED: a novel predictor-encoder-decoder model for Alzheimer drug molecular generation.

Alzheimer's disease (AD) is a gradually advancing neurodegenerative disorder characterized by a concealed onset. Acetylcholinesterase (AChE) is an efficient hydrolase that catalyzes the hydrolysis of acetylcholine (ACh), which regulates the concentration of ACh at synapses and then terminates ACh-mediated neurotransmission. There are inhibitors to inhibit the activity of AChE currently, but its side effects are inevitable. In various application fields where Al have gained prominence, neural network-based models for molecular design have recently emerged and demonstrate encouraging outcomes. However, in the conditional molecular generation task, most of the current generation models need additional optimization algorithms to generate molecules with intended properties which make molecular generation inefficient. Consequently, we introduce a cognitive-conditional molecular design model, termed PED, which leverages the variational auto-encoder. Its primary function is to adeptly produce a molecular library tailored for specific properties. From this library, we can then identify molecules that inhibit AChE activity without adverse effects. These molecules serve as lead compounds, hastening AD treatment and concurrently enhancing the AI's cognitive abilities. In this study, we aim to fine-tune a VAE model pre-trained on the ZINC database using active compounds of AChE collected from Binding DB. Different from other molecular generation models, the PED can simultaneously perform both property prediction and molecule generation, consequently, it can generate molecules with intended properties without additional optimization process. Experiments of evaluation show that proposed model performs better than other methods benchmarked on the same data sets. The results indicated that the model learns a good representation of potential chemical space, it can well generate molecules with intended properties. Extensive experiments on benchmark datasets confirmed PED's efficiency and efficacy. Furthermore, we also verified the binding ability of molecules to AChE through molecular docking. The results showed that our molecular generation system for AD shows excellent cognitive capacities, the molecules within the molecular library could bind well to AChE and inhibit its activity, thus preventing the hydrolysis of ACh.

Nature's Toolbox for Alzheimer's Disease: A Review on the Potential of Natural Products as Alzheimer's Disease Drugs

Numerous clinical trials involving natural products have been conducted to observe cognitive performances and biomarkers in Alzheimer's Disease (AD) patients. However, to date, no natural-based drugs have been approved by the FDA as treatments for AD. In this review, natural product-based compounds that were tested in clinical trials from 2011 to 2023, registered at www.clinicaltrials.gov were reviewed. Thirteen compounds, encompassing 7 different mechanisms of action were covered. Several observations were deduced, which are: i) several compounds showed cognitive improvement, but these improvements may not extend to AD, ii) compounds that are endogenous to the human body showed better outcomes, and iii) Docosahexaenoic acid (DHA) and cerebrolysin had the most potential as AD drugs among the 13 compounds. Based on the current findings, natural products may be more suitable as a supplement than AD drugs in most cases. However, the studies covered here were conducted in a relatively short amount of time, where compounds acting on AD pathways may take time to show any effect. Given the diverse pathways that these natural products are involved in, they may potentially produce synergistic effects that would be beneficial in treating AD. Additionally, natural products benefit from both physicochemical properties being in more favorable ranges and active transport playing a more significant role than it does for synthetic compounds.

Disruption of sphingomyelin synthase 2 gene alleviates cognitive impairment in a mouse model of Alzheimer’s disease

The membrane raft accommodates the key enzymes synthesizing amyloid β (Aβ). One of the two characteristic components of the membrane raft, cholesterol, is well known to promote the key enzymes that produce amyloid-β (Aβ) and exacerbate Alzheimer’s disease (AD) pathogenesis. Given that the raft is a physicochemical platform for the sound functioning of embedded bioactive proteins, the other major lipid component sphingomyelin may also be involved in AD. Here we knocked out the sphingomyelin synthase 2 gene (SMS2) in 3xTg AD model mice by hybridization, yielding SMS2KO mice (4S mice). The novel object recognition test in 9/10-month-old 4S mice showed that cognitive impairment in 3xTg mice was alleviated by SMS2KO, though performance in the Morris water maze (MWM) was not improved. The tail suspension test detected a depressive trait in 4S mice, which may have hindered the manifestation of performance in the wet, stressful environment of MWM. In the hippocampal CA1, hyperexcitability in 3xTg was also found alleviated by SMS2KO. In the hippocampal dentate gyrus of 4S mice, the number of neurons positive with intracellular Aβ or its precursor proteins, the hallmark of young 3xTg mice, is reduced to one-third, suggesting an SMS2KO-led suppression of syntheses of those peptides in the dentate gyrus. Although we previously reported that large-conductance calcium-activated potassium (BK) channels are suppressed in 3xTg mice and their recovery relates to cognitive amelioration, no changes occurred by hybridization. Sphingomyelin in the membrane raft may serve as a novel target for AD drugs.

Effectiveness of Apolipoprotein E Targeted Therapeutic Drugs for Alzheimer’s Disease: A Systematic Review and Meta-analysis (P11-9.008)

Effectiveness of Apolipoprotein E Targeted Therapeutic Drugs for Alzheimer’s Disease: A Systematic Review and Meta-analysis (P11-9.008)

Nanomaterials-mediated lysosomal regulation: a robust protein-clearance approach for the treatment of Alzheimer's disease.

Alzheimer's disease is a debilitating, progressive neurodegenerative disorder characterized by the progressive accumulation of abnormal proteins, including amyloid plaques and intracellular tau tangles, primarily within the brain. Lysosomes, crucial intracellular organelles responsible for protein degradation, play a key role in maintaining cellular homeostasis. Some studies have suggested a link between the dysregulation of the lysosomal system and pathogenesis of neurodegenerative diseases, including Alzheimer's disease. Restoring the normal physiological function of lysosomes hold the potential to reduce the pathological burden and improve the symptoms of Alzheimer's disease. Currently, the efficacy of drugs in treating Alzheimer's disease is limited, with major challenges in drug delivery efficiency and targeting. Recently, nanomaterials have gained widespread use in Alzheimer's disease drug research owing to their favorable physical and chemical properties. This review aims to provide a comprehensive overview of recent advances in using nanomaterials (polymeric nanomaterials, nanoemulsions, and carbon-based nanomaterials) to enhance lysosomal function in treating Alzheimer's disease. This review also explores new concepts and potential therapeutic strategies for Alzheimer's disease through the integration of nanomaterials and modulation of lysosomal function. In conclusion, this review emphasizes the potential of nanomaterials in modulating lysosomal function to improve the pathological features of Alzheimer's disease. The application of nanotechnology to the development of Alzheimer's disease drugs brings new ideas and approaches for future treatment of this disease.

Alzheimer's disease drug development pipeline: 2024

New therapies to prevent or delay the onset of symptoms, slow progression, or improve cognitive and behavioral symptoms of Alzheimer's disease (AD) are needed. We interrogated clinicaltrials.gov including all clinical trials assessing pharmaceutical therapies for AD active in on January 1, 2024. We used the Common Alzheimer's Disease Research Ontology (CADRO) to classify the targets of therapies in the pipeline. There are 164 trials assessing 127 drugs across the 2024 AD pipeline. There were 48 trials in Phase 3 testing 32 drugs, 90 trials in Phase 2 assessing 81 drugs, and 26 trials in Phase 1 testing 25 agents. Of the 164 trials, 34% (N = 56) assess disease-modifying biological agents, 41% (N = 68) test disease-modifying small molecule drugs, 10% (N = 17) evaluate cognitive enhancing agents, and 14% (N = 23) test drugs for the treatment of neuropsychiatric symptoms. Compared to the 2023 pipeline, there are fewer trials (164vs. 187), fewer drugs (127vs. 141), fewer new chemical entities (88vs. 101), and a similar number of repurposed agents (39vs. 40). In the 2024 Alzheimer's disease drug development pipeline, there are 164 clinical trials assessing 127 drugs.The 2024 Alzheimer's disease drug development pipeline has contracted compared to the 2023 Alzheimer pipeline with fewer trials, fewer drugs, and fewer new chemical entities.Drugs in the Alzheimer's disease drug development pipeline target a wide array of targets; the most common processes targeted include neurotransmitter receptors, inflammation, amyloid, and synaptic plasticity.The total development time for a potential Alzheimer's disease therapy to progress from nonclinical studies to FDA review is approximately 13 years.

Diosmetin derivatives as multifunctional anti-AD ligands: Design, synthesis, and biological evaluation.

With the increasing aging population, rational design of drugs for Alzheimer's disease (AD) treatment has become an important research area. Based on the multifunctional design strategy, four diosmetin derivatives (1-4) were designed, synthesized, and characterized by 1H NMR, 13C NMR, and MS. Docking study was firstly applied to substantiate the design strategies and then the biological activities including cholinesterase inhibition, metal chelation, antioxidation and β-amyloid (Aβ) aggregation inhibition invitro were evaluated. The results showed that 1-4 had good acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition, metal chelation (selective chelation of Cu2+ ions), antioxidation, self-induced, Cu2+-induced, and AChE-induced Aβ aggregation inhibition activities, and suitable blood-brain barrier (BBB) permeability. Especially, compound 3 had the strongest inhibitory effect on AChE (10-8 M magnitude) and BuChE (10-7 M magnitude) and showed the best inhibition on AChE-induced Aβ aggregation with 66.14% inhibition ratio. Furthermore, compound 3 could also reduce intracellular reactive oxygen species (ROS) levels in Caenorhabditis elegans and had lower cytotoxicity. In summary, 3 might be considered as a potential multifunctional anti-AD ligand.

Anti-amyloid therapies: are they effective and safe?

Abstract After numerous unsuccessful attempts to create a therapy that could alter the course of Alzheimer’s disease, first monoclonal antibodies targeting amyloid-β in the brain have finally shown consistent evidence of clinical effectiveness. These therapies not only slow the progression of the disease, but also show positive results in secondary clinical outcomes and reduced amyloid-β levels on PET scans. This presentation will examine the main features of the previous failed trials and explore possible reasons for their lack of success in developing a treatment for early-stage Alzheimer’s disease. It will also compare the safety profiles of various antibodies and point out precautions that should be taken when using them in regular clinical practice. Furthermore, it will be discussed how blood-based biomarkers can revolutionize the clinical care pathway, making it easier to adopt antibody treatments. A comprehensive model that integrates case-finding and treatment across various healthcare sectors will be proposed. In conclusion, we may have made a significant breakthrough by demonstrating that reducing amyloid-β levels leads to clinical benefits, not just changes in biomarkers. As the new generation of drugs becomes more commonly used, we will see whether their statistical effectiveness translates into meaningful clinical changes. This could mark the start of a new phase in the development of drugs for Alzheimer’s disease.Disclosure of InterestNone Declared

Advances in Developing Small Molecule Drugs for Alzheimer's Disease.

Alzheimer's disease (AD) is the most common type of dementia among middle-aged and elderly individuals. Accelerating the prevention and treatment of AD has become an urgent problem. New technology including Computer-aided drug design (CADD) can effectively reduce the medication cost for patients with AD, reduce the cost of living, and improve the quality of life of patients, providing new ideas for treating AD. This paper reviews the pathogenesis of AD, the latest developments in CADD and other small-molecule docking technologies for drug discovery and development; the current research status of small-molecule compounds for AD at home and abroad from the perspective of drug action targets; and the development trend of new drug development for AD in the future.

Development of a novel sensor for the detection of donepezil hydrochloride as Alzheimer's disease drug utilizing CuO-TiO2 hybrid nanostructures

In this study, donepezil hydrochloride (DZ HCl), a crucial medication for the treatment of Alzheimer's disease, is detected using a new sensor built on CuO-TiO2 hybrid nanostructures. The sensor showed improved performance characteristics with a computed limit of quantitation of 0.211 and a limit of detection of 0.063. These qualities included improved stability, selectivity, and sensitivity. The fabrication process demonstrated repeatability, with a 4.27% relative standard deviation. After 10 successive readings, the sensor maintained 95% of its initial response, demonstrating its long-term stability. By quantifying DZ HCl in urine samples, the practical applicability of the sensor was confirmed. Remarkably, the sensor achieved a remarkable recovery rate of 97.00–99.41% and a suitable relative standard deviation range of 3.29–4.71%. The results of this work contribute to the development of trustworthy electrochemical sensors for medicinal chemicals and have prospective uses in pharmacological, biological, and therapeutic fields.

Nanomedicine: A New Frontier in Alzheimer's Disease Drug Targeting.

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder affecting elderly individuals, characterized by progressive cognitive decline leading to dementia. This review examines the challenges posed by anatomical and biochemical barriers such as the blood-brain barrier (BBB), blood-cerebrospinal fluid barrier (BCSFB), and p-glycoproteins in delivering effective therapeutic agents to the central nervous system (CNS) for AD treatment. This article outlines the fundamental role of acetylcholinesterase inhibitors (AChEIs) and NMDA(N-Methyl-D-Aspartate) receptor antagonists in conventional AD therapy and highlights their limitations in terms of brain-specific delivery. It delves into the intricacies of BBB and pglycoprotein-mediated efflux mechanisms that impede drug transport to the CNS. The review further discusses cutting-edge nanomedicine-based strategies, detailing their composition and mechanisms that enable effective bypassing of BBB and enhancing drug accumulation in brain tissues. Conventional therapies, namely AChEIs and NMDA receptor antagonists, have shown limited efficacy and are hindered by suboptimal brain penetration. The advent of nanotechnology-driven therapeutic delivery systems offers promising strategies to enhance CNS targeting and bioavailability, thereby addressing the shortcomings of conventional treatments. Various nanomedicines, encompassing polymeric and metallic nanoparticles (MNPs), solid lipid nanoparticles (SLNs), liposomes, micelles, dendrimers, nanoemulsions, and carbon nanotubes, have been investigated for their potential in delivering anti-AD agents like AChEIs, polyphenols, curcumin, and resveratrol. These nanocarriers exhibit the ability to traverse the BBB and deliver therapeutic payloads to the brain, thereby holding immense potential for effective AD treatment and early diagnostic approaches. Notably, nanocarriers loaded with AChEIs have shown promising results in preclinical studies, exhibiting improved therapeutic efficacy and sustained release profiles. This review underscores the urgency of innovative drug delivery approaches to overcome barriers in AD therapy. Nanomedicine-based solutions offer a promising avenue for achieving effective CNS targeting, enabling enhanced bioavailability and sustained therapeutic effects. As ongoing research continues to elucidate the complexities of CNS drug delivery, these advancements hold great potential for revolutionizing AD treatment and diagnosis.

Design, Synthesis and Molecular Modeling Study of Radiotracers Based on Tacrine and Its Derivatives for Study on Alzheimer’s Disease and Its Early Diagnosis

From 1993 to 2013, tacrine was an approved drug for Alzheimer’s disease. Due to its strong inhibitory properties towards cholinesterase, tacrine causes an increase in the level of the neurotransmitter acetylcholine in the cholinergic system of the central nervous system. This work presents a review of articles in which tacrine or its derivatives labeled with the radionuclides 3H, 11C, 14C, 123I, 99mTc and 68Ga were used as vectors in radiotracers dedicated to the diagnosis of Alzheimer’s disease. The possibility of clinical applications of the obtained radiopreparations was assessed by analyzing their physicochemical properties, ability to cross the blood–brain barrier and the level of uptake in the brain. Based on these data, it was shown that radiopreparations based on the tacrine molecule or its very close analogues retain the ability to cross the blood–brain barrier, while radiopreparations containing a more modified tacrine molecule (connected via a linker to a radionuclide chelator) lose this ability. This is probably the result of the addition of a chelator, which significantly increases the size of the radiopreparation and reduces its lipophilicity. Computer docking studies of tacrine derivatives and/or radiopreparations showed how these compounds bind to the active sites of acetyl- and butyrylcholinesterase.